1. Field of the Invention
The present invention relates to an apparatus of withdrawing the filter plugs used in the manufacture of filter-tipped cigarettes.
2. Discussion of the Prior Art
Known apparatuses of this type have the drawback that at the desired high speeds of withdrawal by the rotation of the fluted drum, the flutes in the drum are irregularly filled, especially because of the bridges that tend to be formed in the mass of the moving rod-like articles contained in the hopper. The fact of leaving some drum flutes empty brings about some problems in the subsequent use of the rod-like articles.
The object of the invention is an apparatus for withdrawing and singling rod-like articles contained in a feeding hopper, the bottom of which is at least in part formed by a rotary, possibly suction, fluted drum receiving one rod-like article in each one of its flutes and carrying the thus collected rod-like articles out of the feeding hopper, where it generally transfers them to a successive conveyor for their further use.
The object of the present invention is to eliminate the above-described drawback, and to impart a rolling movement to the rod-like articles lying within the hopper in a zone that is adjacent to the drum and extends over a wide sector thereof. This avoids the forming of bridges, while simultaneously applying on the rod-like articles a force being substantially directed radially toward the drum, so as to promote the insection of said articles into the flutes in said drum.
To this end, according to the invention, at the inside of the feeding hopper a guiding device is provided over the ascending sector of the rotary fluted drum. The grining extends in an inclined direction substantially tangential to the drum, at a distance therefrom that corresponds to a multiple of the diameter of the rod-like articles, and with the fluted drum the guiding device forms a duct having at least one convergently shaped inlet end.
The guiding device may be, as a whole or in part, flat or arcuate, with the concave side turned toward the drum. In any case, the guiding device applies to the rod-like articles a pressure being directed radially toward the fluted drum, when the mass of moving rod-like articles penetrates in the convergently shaped inlet or inlets of the duct formed between the guiding device and the fluted drum.
The guiding device according to the invention may be an immovable device, so that it forms a stationary flat or arcuate surface on which the rod-like articles roll and the grinding device makes up the adjacent layer of the mass of rod-like articles filling the duct between the guiding device and the fluted drum. The rolling of the rod-like articles in the layer that is adjacent to the immovable guiding device, is transmitted also to the other rod-like articles which are thus kept moving, whereby the forming of bridges is avoided.
This effect of moving the rod-like articles contained in the feeding hopper, and of keeping them moving, may be further increased by imparting to the guiding device its own motion, such as, for example, an alternate oscillatory motion and/or a motion of translation in the longitudinal direction of the guiding device. Such a longitudinally translational motion may be a continuous motion in the same direction, for example, in the direction concordant with, or opposite to the rotation of the fluted drum, or, preferably, it may even be an alternate motion, and can be obtained in a particularly simple manner when the guiding device is made in the form of a band.